Recent trends indicate that the future will progress towards sensor-actuator based automation in various sectors including buildings, communities/cities, transportation, energy, etc. Experts predict that in the coming decades there will be a fabric of trillions of sensor-actuator devices embedded into our surroundings. This fabric will bring about integrated automation that will greatly improve the efficiency of the environment and/or resources as well as the quality of living for those within the environment.
Today, accessing (reading and writing) from/to a sensor-actuator is accomplished using various IP accessing techniques such as Web Services (e.g., the known “Restful API” including optimized versions of it such as the constrained application protocol (CoAP) along with IPv6 over Low power Wireless Personal Area Networks (6LoWPAN), etc.) via gateway routers using end-to-end IPv6 approaches where data could be gathered form a central location or using a hierarchical approach with remote agents hosted on edge routers. However, these techniques require some level of synchronization as well as multi-hop routing control protocols among sensors/actuators in a given sensor-actuator fabric cluster, in order to provide access paths between an edge gateway router (or border router) and a sensor/actuator of interest. This is not always not feasible, because all sensors/actuators in a given sensor-actuator grid are not created equal in terms of cost/power/performance/processing power/radio link availability/etc. Furthermore, new architectures are emerging consisting of using minimalistic connected objects (MCOs), thus reducing complexity in avoiding the support of complex protocols in a low power and lossy network (LLN). Moreover, the sheer volume of data generated by the sensors/actuators in a sensor-actuator fabric cluster may make it infeasible for the data to be transmitted to/from the gateway router. Indeed, low power data links usually only provide a few Kbits/s of bandwidth (e.g., power-line communication (PLC) and wireless/radio frequency (RF) shared-media protocols), and will not likely be able to carry large amounts of traffic, not to mention limitations when using battery-operated devices. In other cases, it might be useful for the user to obtain/set data on-demand as it preserves the relevancy of the data with respect to time and location.
In addition, another aspect of the typical sensor-actuator fabric is that the sensors/actuators form an arbitrarily connected network in which the quality of the link between any two sensor/actuator nodes may degrade randomly. This may cause complete loss of the links or severe errors, resulting in path unavailability between the requesting gateway router or central controller (e.g., a network management server (NMS)) and the target sensor/actuator.